/*  * Copyright 2004-2005 OpenSymphony  *  * Licensed under the Apache License, Version 2.0 (the "License"); you may not  * use this file except in compliance with the License. You may obtain a copy  * of the License at  *  *   http://www.apache.org/licenses/LICENSE-2.0  *    * Unless required by applicable law or agreed to in writing, software  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the  * License for the specific language governing permissions and limitations  * under the License. *  *//* * Previously Copyright (c) 2001-2004 James House */package org.quartz.utils;import java.sql.Connection;import java.sql.SQLException;import java.util.HashMap;/** * <p> * Manages a collection of ConnectionProviders, and provides transparent access * to their connections. * </p> *  * @see ConnectionProvider * @see PoolingConnectionProvider * @see JNDIConnectionProvider * @see org.quartz.utils.weblogic.WeblogicConnectionProvider *  * @author James House * @author Sharada Jambula * @author Mohammad Rezaei */public class DBConnectionManager {    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Constants.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    public static final String DB_PROPS_PREFIX = "org.quartz.db.";    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Data members.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    private static DBConnectionManager instance = new DBConnectionManager();    private HashMap providers = new HashMap();    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Constructors.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    /**     * <p>     * Private constructor     * </p>     *       */    private DBConnectionManager() {    }    /*     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     *      * Interface.     *      * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~     */    public void addConnectionProvider(String dataSourceName,            ConnectionProvider provider) {        this.providers.put(dataSourceName, provider);    }    /**     * Get a database connection from the DataSource with the given name.     *      * @return a database connection     * @exception SQLException     *              if an error occurs, or there is no DataSource with the     *              given name.     */    public Connection getConnection(String dsName) throws SQLException {        ConnectionProvider provider = (ConnectionProvider) providers                .get(dsName);        if (provider == null)                throw new SQLException("There is no DataSource named '"                        + dsName + "'");        return provider.getConnection();    }    /**     * Get the class instance.     *      * @return an instance of this class     */    public static DBConnectionManager getInstance() {        // since the instance variable is initialized at class loading time,        // it's not necessary to synchronize this method */        return instance;    }    /**     * Shuts down database connections from the DataSource with the given name,     * if applicable for the underlying provider.     *     * @return a database connection     * @exception SQLException     *              if an error occurs, or there is no DataSource with the     *              given name.     */    public void shutdown(String dsName) throws SQLException {        ConnectionProvider provider = (ConnectionProvider) providers        .get(dsName);        if (provider == null)            throw new SQLException("There is no DataSource named '"                    + dsName + "'");        provider.shutdown();    }    }